Noxious weeds are plant species that are designated as "noxious weeds" in the Alberta weed regulation. Noxious weeds must be controlled, meaning their growth or spread needs to be prevented.

Origin

Lesser burdock, also called common burdock, was introduced from Europe in the 17th century for its medicinal and culinary purposes.

Legislated Because

This species can spread rapidly through the dispersal of its hooked fruits, which attach themselves to clothing and animal fur. These burrs can cause eye, nose, and mouth injuries in livestock. There have also been reported cases of birds and bats becoming entangled in the burrs.

Description

The flower heads of lesser burdock are pink-purple, up to 2.5 cm wide and have stalks that are usually 0-3 cm long.

The leaves are heart-shaped, green on the top side, white on the underside, and are alternately arranged along the stem. The leaf stalks are hollow.

Plants produce large, brown fruits with hooked barbs that are characteristic to this plant.